The proposed research consists of three separate but related studies of the clinical application of Levo-alpha-Acethylmethadol (LAAM) with heroin addicts. The first two of these studies will evaluate induction strategies. Study 1 will compare three schedules for street (i.e., non maintenance patients) and Study 2 will investigate three comparable schedules in methadone maintenance patient who will be crossed-over to LAAM. In each instance, the schedules differ in terms of the use of supplementary methadone or LAAM. The target sample for each study will be 100 patients per group or 300 per study. The remaining study will evaluate LAAM as a detoxification agent. This study will take advantage of the fact that 600 patients will be inducted onto LAAM in the first two studies and some unknown number will subsequently elect or be forced to detoxify. This will provide an opportunity to compare methadone and LAAM as detoxification agents in this manintence group.